p29 pre-pulsar shuttle

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p29 pre-pulsar shuttle
x = 28, y = 28, rule = B3/S23 15bo$13b3o$12bo$12b2o2$bo$obo3b3o$bo4bobo6b2o$6b3o6b2o3$19b2o$6b3o10b 2o5b2o$bo4bobo17bo$obo3b3o15bobo$bo22b2o4$13b3o3b3o$13bobo3bobo$13b3o 3b3o4$13bo7bo$12bobo5bobo$13bo7bo! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ AUTOSTART ]] #C [[ GPS 5 ZOOM 10 LOOP 29 ]]
Pattern type Oscillator
Oscillator type Shuttle
Number of cells 54
Bounding box 28×28
Period 29
Mod 29
Heat 41.5
Volatility 0.90
Strict volatility 0.90
Discovered by David Buckingham
Year of discovery 1980

p29 pre-pulsar shuttle (or prime[1]) is a period-29 shuttle oscillator discovered by David Buckingham on August 2, 1980,[1] making it the first oscillator of that period to be found. In terms of its 54 cells it is the smallest known period-29 oscillator.[2] The oscillator works by combining the 15-generation, two-tub pre-pulsar shuttle mechanism used in Eureka with a 14-generation pre-pulsar shuttle mechanism. Hassling pre-pulsars in this way was the only known way of constructing period 29 oscillators until the discovery of the p29 traffic-farm hassler. In September 1994 Bill Gosper found that two copies of pre-pulsar shuttle 29 could be used to hassle a pentadecathlon. Gosper used this to construct the p58 toadsucker.

Some variants of this shuttle are shown below. A 42-glider synthesis is known for one variant, 56P29.

A fully symmetric variant of this oscillator was first known to appear semi-naturally in December 2014, in a soup found by Richard Schank using apgsearch.[3]

Image gallery

Generation 4 reveals two pre-pulsars (black) being hassled by a 15-generation mechanism (green) and a 14-generation mechanism (red).
A slightly larger version of this oscillator, 56P29, with just one pre-pulsar (black) and an alternate 14-generation stabilization (red)
RLE: here
A much larger version of this oscillator with four pre-pulsars
RLE: here

See also


  1. 1.0 1.1 Dean Hickerson's oscillator stamp collection. Retrieved on December 8, 2019.
  2. "Class 2 Objects Catalog". Retrieved on June 10, 2009.
  3. Richard Schank (December 18, 2014). Re: Soup search results (discussion thread) at the ConwayLife.com forums

External links

  • 54P29.1 at Heinrich Koenig's Game of Life Object Catalogs